From 48265827687f47243606fd272e5738e11074a3c8 Mon Sep 17 00:00:00 2001
From: Kay Lovelace <kay@herostrat.us>
Date: Sun, 19 Mar 2017 15:16:40 +0000
Subject: [PATCH] Include anonymous functions in stack traces

Some functions are more anonymous than others. Node does a pretty
good job of naming functions like this:

```js
const fn = () => { throw "whoops!" } // <-- gets named `fn` in stacktraces
```

But in some cases a function genuinely has no name, e.g.

```js
const fn = () => () => { throw "whoops!" } // <-- inner function has no name!
```

This means we get stacktraces like this:

```
whoops!
  path/to/file.js:1:1
  Test.t (test.js:1:1)
```

Before this commit, the regex in `extract-stack.js` was not anticipating
stacktraces of this form, and would simply filter out the anonymous functions.
This made my life a little more awkward, as I could only see the failing test
line and the error, not the code that was actually erroring.

This commit adds another regex to `extract-stack.js` which matches on anonymous
function stacktrace lines too.
---
 lib/extract-stack.js                        |  2 +-
 test/cli.js                                 |  8 ++++++++
 test/extract-stack.js                       | 10 ++++++++++
 test/fixture/error-in-anonymous-function.js |  9 +++++++++
 4 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 test/fixture/error-in-anonymous-function.js

diff --git a/lib/extract-stack.js b/lib/extract-stack.js
index 64f63db1c..c6e0fea86 100644
--- a/lib/extract-stack.js
+++ b/lib/extract-stack.js
@@ -1,5 +1,5 @@
 'use strict';
-const stackLineRegex = /^.+ \(.+:[0-9]+:[0-9]+\)$/;
+const stackLineRegex = /^.+( \(.+:[0-9]+:[0-9]+\)|:[0-9]+:[0-9]+)$/;
 
 module.exports = stack => {
 	return stack
diff --git a/test/cli.js b/test/cli.js
index 021757221..3012b92ab 100644
--- a/test/cli.js
+++ b/test/cli.js
@@ -105,6 +105,14 @@ test('throwing a named function will report the to the console', t => {
 	});
 });
 
+test('include anonymous functions in error reports', t => {
+	execCli('fixture/error-in-anonymous-function.js', (err, stdout, stderr) => {
+		t.ok(err);
+		t.match(stderr, /test\/fixture\/error-in-anonymous-function\.js:4:8/);
+		t.end();
+	});
+});
+
 test('improper use of t.throws will be reported to the console', t => {
 	execCli('fixture/improper-t-throws.js', (err, stdout, stderr) => {
 		t.ok(err);
diff --git a/test/extract-stack.js b/test/extract-stack.js
index 362e825fa..d0fc8612c 100644
--- a/test/extract-stack.js
+++ b/test/extract-stack.js
@@ -34,3 +34,13 @@ test('strip beginning whitespace from stack', t => {
 	t.is(extractStack(stack), 'Test.t (test.js:1:1)');
 	t.end();
 });
+
+test('includes anonymous function lines', t => {
+	const stack = [
+		'error message',
+		'path/to/test.js:1:1'
+	].join('\n');
+
+	t.is(extractStack(stack), 'path/to/test.js:1:1');
+	t.end();
+});
diff --git a/test/fixture/error-in-anonymous-function.js b/test/fixture/error-in-anonymous-function.js
new file mode 100644
index 000000000..db5f0d571
--- /dev/null
+++ b/test/fixture/error-in-anonymous-function.js
@@ -0,0 +1,9 @@
+import test from '../../';
+
+const getAnonymousFn = () => () => {
+	throw Error();
+};
+
+test(t => {
+	getAnonymousFn()();
+});